1. Field of the Invention
The present invention relates to a pendent fire protection sprinkler with a drop-down deflector. The present invention further relates to concealed pendent sprinklers for residential applications.
2. Related Art
Fire protection sprinklers conventionally are connected to a conduit to receive pressurized fire-extinguishing fluid, such as water. A typical sprinkler has a base with a threaded portion for connection to the conduit and an output orifice to output the fluid to provide fire control and/or suppression. The output orifice is sealed by a seal cap, which is held in place by a release mechanism. The release mechanism is designed to release the cap under predetermined conditions, thereby initiating the flow of fire-extinguishing fluid. A typical release mechanism includes a thermally-responsive element, e.g., a frangible bulb or a fusible link, and may include a latching mechanism.
A sprinkler may be mounted on a fluid conduit running along a ceiling and may either depend downward from the conduit, which is referred to as a “pendent” configuration, or may be mounted on a wall, a certain distance below the ceiling, which is referred to as a “horizontal sidewall” configuration.
Certain conventional sprinklers have a pair of arms that extend from a base, wherein the arms connect at a hub. The hub is spaced apart from the output orifice of the base and is aligned with a longitudinal axis thereof. The hub may have a set-screw configured to apply a force to the thermally-responsive element and latching mechanism thereby maintaining the seal cap in a position which seals the output orifice. A deflector may be mounted on the hub, transverse to the output orifice, to provide dispersion of the output fluid.
Other sprinklers have a deflector that is attached by a pair of arms that extend from the base of the sprinkler, but do not meet at a hub. In such sprinklers, the thermally-responsive element holds the seal cap in place without being held in compression by a hub. For example, U.S. Pat. No. 4,976,320 shows a sprinkler having a deflector attached to the body with arms that do not meet at a hub. The arms extend from the sprinkler body, and a drop-down deflector is attached to the sprinkler via two guide pins, which are installed in holes in a bent portion at the bottom of each arm. U.S. Pat. No. 5,664,630 shows another example of a sprinkler with a drop-down deflector.